readarr post processing script

Reference: https://github.com/RandomNinjaAtk/docker-lidarr-extended/issues/163

Only things this does is convert MP3s to M4B's with chapters...

Inspired by this script (https://github.com/Geremia/chapterize/blob/main/chapterize.py) and other sources...

root/scripts/readarr-pp.bash

@@ -0,0 +1,74 @@
+#!/usr/bin/with-contenv bash
+export LC_ALL=C.UTF-8
+export LANG=C.UTF-8
+TITLESHORT="APP"
+ScriptVersion="1.00"
+SECONDS=0
+
+set -e
+set -o pipefail
+
+touch "/config/scripts/logs/readarr-pp.txt"
+chmod 666 "/config/scripts/logs/readarr-pp.txt"
+exec &> >(tee -a "/config/scripts/logs/readarr-pp.txt")
+
+echo "Processing: $1" 
+
+Clean () {
+	if [ $(find "$1" -type f -regex ".*/.*\.\(\m4b|flac\|mp3\|m4a\|alac\|ogg\|opus\)" | wc -l) -gt 0 ]; then
+		find "$1" -type f -not -regex ".*/.*\.\(flac\|mp3\|m4a\|alac\|ogg\|opus\)" -delete
+		find "$1" -mindepth 2 -type f -exec mv "{}" "$1"/ \;
+		find "$1" -mindepth 1 -type d -delete
+	else
+		echo "ERROR: NO AUDIO FILES FOUND" && exit 1
+	fi
+}
+
+Clean "$1"
+
+echo "Creating Chapters File and File list for FFMPEG processing..."
+
+if [ $(find "$1" -type f -iname "*.mp3" | wc -l) -gt 0 ]; then
+    OLDIFS="$IFS"
+    IFS=$'\n'
+    files="$(ls -1v "$1"/*.mp3)"
+    start=0
+    chapterNumber=0
+    concatFileNames=""
+    ffmpegMetadata=""
+    chapterFile="$1/chapters.txt"
+    fileList="$1/list.txt"
+    for i in $(echo "$files"); do
+        chapterNumber=$(( $chapterNumber + 1))
+        if [ -z "$ffmpegMetadata" ]; then
+            ffmpegMetadata=$(ffmpeg -i "$i" -f ffmetadata -v quiet -)
+            echo "$ffmpegMetadata" >> $chapterFile
+            echo "" >> $chapterFile
+        fi
+        #echo "start :: $start"
+        echo "[CHAPTER]" >> $chapterFile
+        echo "TIMEBASE=1/1000" >> $chapterFile
+        echo "START=$start" >> $chapterFile
+        seconds=$(sox "$i" -n stat |& head -2 | tail -1 | grep -o '[[:digit:]]*' | head -1)
+        seconds=$(( $seconds * 1000 ))
+        end=$(( $start + $seconds - 1 ))
+        #echo "seconds :: $seconds"
+        #echo "end :: $end"
+        echo "END=$end" >> $chapterFile
+        echo "title=Chapter \#$chapterNumber" >> $chapterFile
+        echo "" >> $chapterFile
+        start=$(( $end + 1 ))
+        echo "file '$i'" >> $fileList
+
+        
+    done
+    IFS="$OLDIFS"
+    ffmpeg -f concat -safe 0 -i "$fileList" -i "$chapterFile" -map_metadata 1 -vn -acodec copy "$1/output.mp4"
+    mv "$1/output.mp4" "$1/audiobook.m4b"
+    find "$1" -type f -iname "*.mp3" -delete
+    rm "$chapterFile"
+    rm "$fileList"
+fi
+duration=$SECONDS
+echo "Post Processing Completed in $(($duration / 60 )) minutes and $(($duration % 60 )) seconds!"
+exit